title: Thioflavin T hydroxylation at basic pH and its effect on amyloid fibril detection.
abstract: The fluorescent dye thioflavin T (ThT) is commonly used for in situ amyloid fibril detection. In this work, we focused on the spectroscopic properties and chemical stability of ThT in aqueous solution as a function of pH, temperature, and dye concentration. A reversible hydroxylation process occurs in alkaline solutions, which was characterized using a combination of UV-vis absorption spectroscopy, proton NMR, and density functional theory (DFT). On the basis of these studies, we propose a chemical structure for the hydroxylated form. Finally, by means of fluorescence spectroscopy, ThT hydroxylation effects on in situ amyloid detection have been investigated, providing new insights on the efficiency of the ThT assay for quantitative fibril evaluation at basic pH.
authors.affiliation: Dipartimento di Scienze Fisiche e Astronomiche, Università degli Studi di Palermo, Palermo, Italy. fodera@fisica.unipa.it
authors.forename: Vito
authors.initials: V
authors.lastname: Foderà
authors.forename: Minna
authors.initials: M
authors.lastname: Groenning
authors.forename: Valeria
authors.initials: V
authors.lastname: Vetri
authors.forename: Fabio
authors.initials: F
authors.lastname: Librizzi
authors.forename: Salvatore
authors.initials: S
authors.lastname: Spagnolo
authors.forename: Claus
authors.initials: C
authors.lastname: Cornett
authors.forename: Lars
authors.initials: L
authors.lastname: Olsen
authors.forename: Marco
authors.initials: M
authors.lastname: van de Weert
authors.forename: Maurizio
authors.initials: M
authors.lastname: Leone
mesh_terms: D000682:Amyloid / Q000032:analysis*; D052160:Benzothiazoles; D006863:Hydrogen-Ion Concentration; D006900:Hydroxylation; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D013844:Thiazoles / Q000737:chemistry*
chemical_list: D000682:Amyloid; D052160:Benzothiazoles; D013844:Thiazoles; C009462:thioflavin T